Gasket is a general name for a static seal which is coupled to a fixed joint surface such as a joint surface of pressure container, tube flange, mechanical apparatus, and the like by using bolts and the like for preventing leakage; various shapes, materials, and the like are used according to the usage condition such as the type of the operating fluid, pressure, and temperature. In contrast to this, the general name of a dynamic seal which is used in a moving part is called packing.
Such terms have different names according to the installation location even for the same type of seal, for example, it is called as O-ring gasket when it used as a static one while it is called O-ring packing when it is used as a dynamic one even though they are same type of O-rings. Although such names are standardized, they are not strictly applied.
FIG. 1 is a drawing illustrating an example for a use aspect of such a gasket. A gasket 100 is installed between the joint surfaces of the tube flanges 200; the gasket 100, installed in this way, prevents the fluid flowing inside the tube from leaking outside the tube. Once the gasket 100 is installed between the tube flanges 200, a bolt 400 is inserted into the hole of the tube flange 200 and the both ends of the bolt is fastened by the nuts 200, 300 in order to prevent the joint surfaces of the tube flanges 200 from being separated. A metal washer 610 and an insulation washer 620 may be coupled in advance when the nuts 200, 300 are being coupled to the bolt 400. And, the bolt 300, which is inserted into the hole of the tube flange 200, may be inserted into the tube flange 200 as being inserted inside the insulation sleeve 500.